A stabilizer bar is a spring element which counteracts body roll of a vehicle, thus improving the vehicle dynamics and the position of the vehicle on the road. The ends of the stabilizer are each connected to the wheel suspension of a vehicle axle. At its two ends, the stabilizer is attached to the vehicle body.
From US 2007/0216126 A1 a method for producing a tubular stabilizer bar is known. The method comprises providing a tubular bar, heating the bar, quenching the bar, and forming the tube to a desired shape by bending operations. The stabilizer bar has a generally elongate central body with first and second stabilizer arms with first and second ends. Following the bending operations, the first and second ends are further formed to a shape that allows attachment of the stabilizer bar to the suspension of an automobile.
From DE 11 2011 100 846 T5 a massive stabilizer produced by cold forming, hardening and tempering of a steel material, is known. After tempering, the stabilizer has a hardness in a middle portion of 400 HV (Vickers hardness number).
From US 2011/0290382 A1 a high-strength stabilizer steel for vehicles is known containing 0.07% to 0.2% C and 1% to 3% Mn and further elements. The stabilizer has a torsion portion and a pair of arm portions with terminals at the ends. US 2014/0060709 A1 discloses a similar stabilizer bar.
From DE 197 58 292 A1 a tubular stabilizer is known having a back portion, bent transition portions, and two leg portions. The wall thickness of the back portion is smaller than the wall thickness of the transition portions.
From DE 10 2009 011 818 A1 a process of producing a stabilizer with two stabilizer bearings is known. For this, the stabilizer is heated in portions and then brought into surface contact with the stabilizer bearing and pressed into position.
From DE 10 2013 101 276 A1 a process of producing a vehicle stabilizer is known. It is proposed that strip material made of a steel alloy with a high manganese content is formed to a tube profile and is subsequently welded into an endless tube. The tube is then drawn over a mandrel, wherein depending on the degree the drawing operation, intermediate annealing can take place. It is mentioned as an advantage that the produced stabilizer does not require any hardening and tempering.
The end portions of stabilizers can have a reduced loading capacity for geometric reasons due to cross-sectional changes, and for material structure reasons due to forming and cooling processes. The wall strengths of the end portions of stabilizers are usually designed according to the forces and loads to be introduced by the wheel carrying components.
In the case of high loads and reduced material thicknesses it may be necessary to provide additional reinforcements, which works against requirements for light weight. Furthermore, leakages may occur at the stabilizer ends which, in the worst possible scenario, may lead to material failure.